1. Field of the Invention
The present invention relates in general to an automatic transmission control and, more particularly, to a gear selector mechanism for an automatic transmission.
2. Description of the Prior Art
An example of a prior art column-mounted gear selector mechanism for an automatic transmission is disclosed in Japanese Utility Model Provisional Publciation No. 60-185750 and is also shown in FIGS. 4 and 5 hereof.
The known gear selector mechanism includes a bracket 1 in the form of a planar plate secured with bolts 1a to a vehicle body panel 26 as a dash board, a steering column assembly 2 supported on the bracket 1 and a control rod 3 disposed in parallel relation to the steering column assembly 2 and rotatably and axially movably supported on same. The control rod 3 is provided with a locking lug 4 projecting radially outwards therefrom. The control rod 3 is further provided with a position guide 5 which is disposed lower than the bracket 1, i.e., on the engine compartment side of the bracket 1. In this connection, the locking lug 4 is disposed on the passenger compartment side of the bracket 1.
A catch lever 7 is disposed on the passenger compartment side of the bracket 1 and is swingably installed on same. The catch lever 7 is formed with an opening 8 for locking engagement with the locking lug 4. A position plate 9 is disposed on the engine compartment side of the bracket 1 and formed with cuts for defining a parking position "P", a neutral position "N", a drive position "D", a second gear position "S" and a first gear position "F" for the control rod 3 and is operatively connected with the position guide 5.
A shift lever 10 is provided for moving the control rod 3 into selected one of the gear positions through movement of the position guide 5 into selected one of the gear positions in the position plate 9. When the control rod 3 is in the parking position, the locking lug 4 is engaged in the opening 8 of the catch lever 7 while pushing a movable contact 12 of a parking switch 11 which is disposed in front of the locking lug 4 and thus turning on the parking switch 11 to indicate that the control rod 3 is in the parking position. The catch lever 7 is disengaged from the locking lug 4 when the control rod 3 is in the parking position and both an ignition switch 28 and a foot brake switch 30 are turned on to energize a solenoid 13 which is installed on the passenger compartment side of the bracket 1. When this is the case, a solenoid pin 13a of the solenoid 13 retracts to pull an arm 7a of the catch lever 7, thus turning the catch lever 7 from the solid line position to the two-dot chain line position in FIG. 5.
A steering wheel 14 is installed on the steering column assembly 2. A select lever 15 is installed on the lower end of the control rod 3 and operatively connected to an automatic transmission control unit 32 for performing shifting of gear in response to variation in the gear position of the control rod 3.
In the foregoing structure, the locking lug 4, etc., are required to be thick enough so as not to be deformed to move into a gear position other than the parking position even when the control rod 3 is forcibly rotated to do so. This however results in increased cost and weight. Further, since the movable contact 12 of the parking switch 11 is disposed so as to extend radially of the control rod 3 and be driven by the locking lug 4 in the same direction, the parking switch 11 is inevitably disposed far away from the control rod 3, resulting in a considerable distance l between the control rod 3 and the parking switch 11 and therefore a difficulty in layout of the parking switch 11.